The invention concerns a nozzle containing a convergent-divergent section in which the outlet section is a predetermined function of the throat section of a type comprising: an unjointed annular assembly of first flaps, each of which is articulated about an axis, called the first axis, of a rigid structure, this assembly constituting a convergent section; an unjointed annular assembly of second flaps, each of which is articulated about an axis, called the second axis, approximately parallel to the aforesaid first axis, of a corresponding first flap, this assembly constituting a divergent section; an articulated linkage coupling each second flap to the rigid structure in order to kinematically secure this second flap to the corresponding first flap so as to slave the outlet section, A.sub.e, to the throat section, A.sub.j, of the nozzle by the relationship A.sub.e =f(A.sub.j); and drives associated with each first flap to cause this flap to pivot about the articulation coupling this latter to the fixed structure.
Known nozzles of this type generally are fitted with a special device to perform the function A.sub.e =f(A.sub.j), or A.sub.e /A.sub.j =f(A.sub.j), and the kinematic link for synchronizing the flaps of the annular assemblies is provided by another device, independent of the first, resulting in a multiplication of the constituent members of the nozzle, an increase in its weight and price, and a reduction in its reliability.